Oman and Qatar were leading efforts to begin ceasefire talks, while mediators said Iran was open to resuming nuclear negotiations if Israel’s attacks stop.

Shapiro served as Deputy Assistant Secretary of Defense for the Middle East until January—charged with, among other things, considering scenarios in which tensions between Israel and Iran escalated into all-out war and preparing U.

Stock markets in the Gulf ended lower on Sunday as Israel and Iran exchanged attacks, raising concerns about a potential broader Middle East conflict.